Fire officials provided new details Sunday about the blaze, which was fueled by flammable materials and ignited ammunition, briefly halting efforts to contain the fire.

Vladimir Drozdoff, 80, was admitted to Maine Medical Center in Portland as a result of burns he suffered in the fire on Saturday. He was listed in critical condition, a hospital spokeswoman reported Sunday.

Drozdoff lived alone at 10 Grove Pond Road, according to Sgt. Ken Grimes of the state fire marshal’s office. Drozdoff’s wife went into a medical care facility several months ago, according to Grimes.

The fire victim was “burned quite badly,” a state police dispatcher reported Saturday. Drozdoff was flown by helicopter to Maine Medical Center after initially being taken to Calais Regional Hospital.

Drozdoff told emergency medical personnel that he discovered the fire and was burned when he attempted to extinguish the flames, Grimes said Sunday.

The fire originated in the first-floor walls and worked its way into the upper portion of the 1½-story house, Cooper Volunteer Fire Department Chief Trevor Flood reported Sunday. By the time firefighters arrived, flames were showing through the roof.

The home was an old wood-frame house, built in the early 1900s, Flood estimated. Flammable materials around and in the house contributed to the blaze although firefighters were able to remove some of them. There were numerous propane tanks and also some cannisters of gasoline, according to Flood.

“There were a lot of (explosions) going on,” said Flood.

The chief attributed most of the explosions to igniting ammunition, which may have been in some type of container. About 12-24 rounds of ammunition ignited, he estimated.

When that occurred, “We just backed off,” said Flood. The roof already had collapsed, and the igniting ammunition was buried under the rubble, he said. Firefighters advanced on the flames again about 30 seconds later, he said.

In addition, one propane tank apparently used for an outdoor grill may have erupted, he said, and a second propane tank “came pretty close” to exploding.

The gasoline apparently was stored to use with a generator that was just outside the front door, Flood suggested. The home also was served by electrical power, he said.

No injuries were reported.

“The biggest challenge was just getting water,” said Flood.

The house is located a little over 500 feet south of Route 191 and about 2 miles north of Cathance Lake. A game warden cut a hole in the ice covering Cathance Lake so firefighters could obtain water near a boat landing. However, it was difficult to gain access because the boat landing area was not entirely clear of snow. Firefighters also set up at a brook about 2 miles away that was more open and drew water from there.

The house burned all the way down into the basement and was a total loss, said Grimes, who investigated the scene on Saturday. He was unable to estimate the value of the house.

The fire did not appear to be suspicious in nature, said Grimes, but the cause was unknown.

Firefighters were on the scene less than 10 minutes after the fire was reported about noon, but within another 10-15 minutes the house was engulfed in flames and started to collapse, said Flood.

“It spread very quickly,” he said.

Firefighters remained on the scene until late Saturday afternoon. Volunteer fire departments from Cooper, Dennysville, Meddybemps, Charlotte, and Alexander went to the home.